Areeba Ansar

Laser–Matter Interaction and Material Processing, Pakistan

Cobalt Ferrite (CoFe?O?) Nanoparticle-Enabled Saturable Absorption for Q-Switched Erbium-Doped Fiber Laser

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Biography

Areeba Ansar is an M.Phil. Physics researcher specializing in optics, photonics, laser physics, and spectroscopy. She completed her M.Phil. in Physics at Mirpur University of Science and Technology (MUST), Pakistan. Currently, she works as a Research Assistant at the Atomic & Laser Physics Laboratory, National Centre for Physics (NCP), Islamabad. Her research interests include Q-switched fiber lasers, laser spectroscopy, nonlinear optics, functional photonic materials, and emerging laser technologies. She has experience in fluorescence and Raman spectroscopy, LIBS, pulsed laser deposition, and fiber laser systems, along with research publications and conference presentations.

Abstract

A passively Q-switched erbium doped fiber laser (EDFL) employing cobalt ferrite (CoFe?O?) nanoparticles as a saturable absorber (SA) is experimentally demonstrated. CoFe?O? nanoparticles were synthesized via the co-precipitation method and characterized using X-ray diffraction (XRD), and scanning electron microscopy (SEM) to investigate their crystal structure, morphology, and particle size. The CoFe?O? nanoparticles were sandwiched between two fiber ferrules using an index-matching gel to form the saturable absorber device. The developed passive saturable absorber integrated into an EDF laser in ring cavity and the characterized pulse is with repetition rates of 103.45kHz, shortest pulse width of 4.66 ?s. A maximum peak power of 6.7 mW and pulse energy of 31.2 nJ were obtained at a pump power of 318 mW, corresponding to an average output power of 3.23 mW. Stable laser oscillation was obtained at a central wavelength of 1557.49 nm with a threshold pump power of 104.6 mW, and a 3 dB bandwidth of 1.77nm. The signal-to-noise ratio (SNR), measured from the first beat note of the RF spectrum, was approximately 53 dB, indicating good pulse stability. The experimental results demonstrate that CoFe?O? nanoparticles possess excellent nonlinear optical characteristics suitable for passive Q-switching and offer a simple, cost-effective, and robust approach for generating stable microsecond pulses in erbium-doped fiber lasers. These findings highlight the potential of CoFe?O? nanoparticles as a promising alternative saturable absorber material for compact, pulsed fiber laser systems, with potential applications in metrology, fiber sensing, medical diagnostics, and optical communications.